This disclosure relates to a small particle, a pin, comprising a nanorod and an attached material. The attached material comprises a material with an index of refraction that is greater than zero. In microscopic applications, the attached material is sufficient to allow the pin to be held in an optical trap. In some embodiments, the pin is sufficient in size to greatly reduce the probability of other pins from being held in the optical trap.
A process of making pins is disclosed. Further disclosed is a method of using a pin in an apparatus to acquire optical signals that arise from the pin and its vicinity. A method of using a plurality of pins in an apparatus to acquire optical signals from a plurality of vicinities of the plurality of pins is also disclosed. The optical signals aid in determining or approximating one or more of: the presence, position, orientation, rates of motion, and optical properties of the pins, and furthermore aid in determining or approximating one or more of: the presence, composition (in whole or part), and properties of an analyte or plurality of analytes or object(s) of interest that is (are) in the vicinity of the pines) or become attached to the pines). The optical signals enable the collection of spectra from the vicinity of the pin. By scanning the pin near, over, or around an object of interest, at least one of the optical signals enables the acquisition of an image of the object of interest. The object(s) of interest may be, but is (are) not limited to be one or more of the following: a molecule, molecules, a cell, cells, a virus, viruses, and a surface.